1. Field of the Invention
The present invention relates to an oral care composition which contains a bis-biguanide compound effective in the retardation of bacterial plaque accumulation on the teeth and more particularly to a dual component dentifrice composition containing a bis-biguanide compound which achieves plaque reduction with substantially less staining of teeth than normally occurs with bis-biguanide compound containing dentiftices.
2. The Prior Art
Dental plaque is a soft deposit which forms on teeth and is comprised of an accumulation of bacteria and bacterial by-products. Plaque adheres tenaciously at the points of irregularity or discontinuity, e.g., on rough calculus surfaces, at the gum line and the like. Besides being unsightly, plaque is implicated in the occurrence of gingivitis and other forms of periodontal disease.
A wide variety of antibacterial agents have been suggested in the art to retard plaque formation and the oral infection and dental disease associated with plaque formation. For example, bis-biguanide compounds such as chlorhexidine are well known to the art for their antibacterial activity and have been used in oral compositions to counter plaque formation by bacterial accumulation in the oral cavity. However, it is also well known that bis-biguanide compounds, when used as dental antiplaque agents cause unsightly staining of teeth. Many procedures have been proposed by the art to reduce such tooth staining: U.S. Pat. Nos. 3,925,543, 3,934,002, 3,937,807, 4,051,234, 4,080,441, 4,256,931, 4,273,759 and 4,886,658. However, the presence of bis-biguanide compounds in dentifrice compositions containing conventional ingredients such as abrasives, anionic surfactants and flavorants which are necessary for adequate cleaning and palatability of the dentifrice, these ingredients are normally incompatible with bis-biguanide compounds, and tend to diminish the bioavailability of such compounds necessary for antiplaque efficacy.
There is a clear need in the art to formulate a dentifrice product capable of delivering a bis-biguanide antibacterial agent whereby the other ingredients used to prepare the dentifrice composition do not inhibit the bioavailability of the bis-biguanide compound concomitant with limited tooth staining caused by the compound.